1. Field of the Invention
This invention relates to methods utilizing synergistic effects between antibiotics and probiotics for improving animal health.
2. Description of the Related Art
Microbial contamination of animals which are very susceptible to microbial pathogens often leads to disease and increased animal morbidity. In commercial animal growing operations where animals may be crowded in facilities where other animals have been previously raised, the likelihood of such contamination is often great. This is particularly true in the poultry industry. Early chick mortality (ECM) is often associated with microbial exposure during incubation, hatching and processing. Pathogenic microorganisms often reside on and within the egg shell, and there is wide dissemination of egg-borne pathogens at hatching. Researchers over the years have tested numerous antimicrobial substances to see if they would improve animal mortality.
Numerous probiotic species have also been tested for efficacy in improving animal health. Many of these tests have utilized various species of the Lactobacillaceae, such as species of Lactobacillus and Streptococcus. Most of these tests have shown limited utility and practicability at best.
Work by Dobrogosz and Lindgren, and their collaborators in the mid-1980's, which has been the subject of a number of publications, however, showed that Lactobacillus reuteri strains are unique in producing an antibiotic substance identified as .beta.-hydroxypropionaldehyde. (See for example, Dobrogosz, WJ, Casas IA, Pagano, GA, Talarico, TL, Sjoberg, B, and M Karlsson, Lactobacillus reuteri and the Enteric Microbiota, in Regulatory and Protective Role of the Normal Microflora, from the Gustafsen Symposium, McMillan Ltd, 1989, pages 283-292; and Dobrogosz, WJ and SE Lindgren, Antibiotic Reuterin, International Application Published under the Patent Cooperation Treaty (PCT), PCT/US88/01423, published November 3, 1988).
Further, L. reuteri was shown to be effective in inhibiting Salmonella, in increasing gastrointestinal villi growth, in increasing animal weight gain, and in improving mortality. In ovo and spraying techniques have been shown to be useful in delivering Lactobacillus reuteri cells to poultry to reduce ECM, as an alternative to traditional antibiotic usage.
While various previous treatments have resulted in improved mortality, there has continued a real need to reduce the number of animal deaths even further.
It is therefore an object of this invention to provide a method of improving animal health, particularly mortality of poultry, such as chickens and turkeys.
Other objects and advantages will be more fully apparent from the following disclosure and appended claims.